A proximity effect in adults' contamination intuitions

Magical beliefs about contagion via contact (Rozin, Nemeroff, Wane, & Sherrod, 1989) may emerge when people overgeneralize real-world mechanisms of contamination beyond their appropriate boundaries (Lindeman & Aarnio, 2007). Do people similarly overextend knowledge of airborne contamination mechanisms? Previous work has shown that very young children believe merely being close to a contamination source can contaminate an item (Springer & Belk 1994); we asked whether this same hyper-avoidant intuition is also reflected in adults' judgments. In two studies, we measured adults' ratings of the desirability of an object that had made contact with a source of contamination, an object nearby that had made no contact with the contaminant, and an object far away that had also made no contact. Adults showed a clear proximity effect, wherein objects near the contamination source were perceived to be less desirable than those far away, even though a separate group of adults unanimously acknowledged that contaminants could not possibly have made contact with either the nearby or far-away object (Study 1). The proximity effect also remained robust when a third group of adults was explicitly told that no contaminating particles had made contact with the objects at any time (Study 2). We discuss implications of our findings for extending the scope of magical contagion effects beyond the contact principle, for understanding the persistence of intuitive theories despite broad acceptance of science-based theories, and for constraining interpretations of the developmental work on proximity beliefs.